Low-temperature synthesis of BiVO4 powders by Pluronic-assisted hydrothermal method: Effect of the surfactant and temperature on the morphology and structural control

Abstract

BiVO4 photocatalyst was successfully synthesized by the hydrothermal method using Pluronic F-127 as morphology-directing agent. BiVO4 powders with a pure monoclinic phase were obtained at 80°C. For optimizing the conditions of synthesis and investigate the product formation mechanism, the temperature of synthesis was systematically investigated. The structural and morphological properties of the as-synthesized BiVO4 photocatalysts were characterized by X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). Nitrogen adsorption measurements (BET) were employed to analyze the specific surface area of the samples. The band gap of the as-prepared BiVO4 samples was determined from the onset of the absorption band of UV–vis diffuse reflectance spectra. The quasi-Fermi potential of electrons of the synthesized samples was determined through pH dependent photovoltage measurements. The photocatalytic activities of the as-synthesized catalysts were evaluated in the photodegradation reaction of an aqueous solution of rhodamine B under visible-light irradiation. The mechanism of formation of the as-prepared BiVO4 samples has also been proposed.